#include "App.h"

void CLoaner::Init(DWORD size)
{
  if (size<=MaxSize) return;
  DWORD Mask =  1  << MaxSize;
  for (DWORD i=MaxSize+ 1 ;i<=size;i++, MaxSize++, Mask<<= 1 ) {
       Queue.insert(CPair( 1 , Mask));
       Cache.insert(CPair(Mask, i));
  }
}

DWORD CLoaner::CalcBits(DWORD pos, DWORD size)
{ 
  DWORD r =  0 ;
  DWORD m =  1 ;
  for (DWORD i= 0 ;i<size;i++, m<<= 1 ) {
      if ((m & pos)!= 0 ) r++;
  }
  return r;
}

bool CLoaner::Check(DWORD pos, DWORD size)
{
  CIter p = Cache.find(pos);
  if (p!=Cache.end()) {
      return (p->second <= size);
  }
  DWORD bc = CalcBits(pos, size);
  if (bc<HWM) return false;
  Init(size);
  for (CIter p=Queue.begin();p!=Queue.end();p=Queue.begin()) {
       if (p->first > HWM) {
           HWM = p->first;
           if (bc<HWM) return false;
       }
       switch (Check(p->second, pos, p->first, size)) {
           case   1 : return true;
           case - 1 : return false;
       }
       Queue.erase(p);
  }
  return false;
}

int CLoaner::Check(DWORD curr, DWORD target, DWORD bitc, DWORD size)
{
  int r =  0 ;
  CIter p = Cache.find(curr);
  if (p==Cache.end()) return false;
  DWORD sz = p->second;
  DWORD LeftMask  =  7 ;
  DWORD RightMask =  7 ;
  DWORD Mask      =  1 ;
  for (DWORD i= 0 ;i<sz;i++, Mask<<= 1 , LeftMask<<= 1 ) {
       if (i> 1 ) {
           if ((curr & RightMask)==Mask) {
               DWORD newpos = curr - (Mask >>  2 );
               if (Cache.find(newpos)==Cache.end()) {
                   Cache.insert(CPair(newpos, sz));
                   Queue.insert(CPair(bitc+ 1 , newpos));
                   if (newpos==target) {
                       r = (sz <= size)? 1 :- 1 ;
                   }
               }
           }
           RightMask <<=  1 ;
       }
       if (i>= 30 ) break;
       if ((curr & LeftMask)==Mask) {
           DWORD newpos = curr + (Mask *  6 ) - Mask;
           if (Cache.find(newpos)==Cache.end()) {
               DWORD newsz = sz;
               if (i+ 2 >=sz) {
                   newsz += i-sz+ 3 ;
               }
               Cache.insert(CPair(newpos, newsz));
               Queue.insert(CPair(bitc+ 1 , newpos));
               if (newpos==target) {
                   r = (newsz <= size)? 1 :- 1 ;
               }
           }
       }
  }
  return r;
}